Preheat oven to 450 degrees. Slice the tube of sausage into 1/2-inch thick pieces; flatten slightly. Fry slowly in a frying pan until done; place on a plate. Place cheese on top and set aside. Meanwhile combine Bisquick, buttermilk, sugar and 2 Tbsp. of melted margarine. Knead 10 times and roll out to 3/4" thick. Cut into biscuits with a cutter. Bake on an ungreased cookie sheet about 11 minutes. Remove from oven and brush tops with the rest of the margarine. Let cool slightly, slice open, and add sausage and cheese.